1. Field of the Invention
Flexible convoluted or corrugated tubing has many uses. Conventionally, special connectors are secured to the ends of the tubing for attachment to specific devices, such as vacuum cleaners. However, it is sometimes desirable to provide for a more inexpensive and simple attachment, such as when the ends of a given length of tubing are to be attached together to form a closed loop which becomes a hose having a continuous loop. Such an attachment might also be used to attach different lengths of tubing to form an even longer tubing, or a longer hose having a continuous loop.
2. Prior Art Statement
It is known to form flexible convoluted elastomeric tubing or rigid pipes in which convolutions are integrally formed with the wall. It is also known to use the convolutions to attach end connectors to the ends of the hose, or to interlock lengths of tubing or pipes.
U.S. Pat. No. 3,727,949 issued to Kleykamp et al., provides a flexible hose having conventional corrugations, and a fitting having a rearwardly hooked surface which engages the interior of the corrugations of the hose. This provides a locked swivel connection of the fitting with a fluid-tight seal. Once engaged, the fitting is not easily removed.
U.S. Pat. No. 3,926,222, issued to Shroy et al., describes a corrugated tubing used for drain tiles, wherein an integrally molded connector is incorporated at the ends. The connector has discontinuing circumferentially spaced cleats which project outwardly in a radial direction to interlock with the inner corrugations.
U.S. Pat. No. 3,958,425, issued to Maroschak, and its parent patent No. 3,802,202, relate to a rigid plastic drain pipe with a collar integrally formed at one end, interconnecting with a mating end of a similar pipe. There is just enough flexibility in the end of the collar to fit around the mating end.
U.S. Pat. No. 4,174,858, issued to Brooks, teaches a helically convoluted hose adapted to interlock with a hose fitting having discontinuous threaded portions.